mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Paul Eggert <eggert@CS.UCLA.EDU>
To: Andrew Morton <akpm@osdl.org>
Cc: Andy Isaacson <adi@hexapodia.org>,
	bug-coreutils@gnu.org, linux-kernel@vger.kernel.org
Subject: Re: dd PATCH: add conv=direct
Date: Wed, 07 Apr 2004 13:46:31 -0700	[thread overview]
Message-ID: <87vfkbms7s.fsf@penguin.cs.ucla.edu> (raw)
In-Reply-To: <20040407111841.78ae0021.akpm@osdl.org> (Andrew Morton's message of "Wed, 7 Apr 2004 11:18:41 -0700")

Andrew Morton <akpm@osdl.org> writes:

> In 2.6 we do the check at open() and fcntl() time.  In 2.4 we don't
> fail until the actual I/O attempt.

This raises the issue of what "dd conv=direct" should do in 2.4
kernels.  I propose that it should report an error and exit, when the
write fails, since conv=direct can't be implemented.  The basic idea
is that on systems that lack direct I/O, conv=direct should fail.

Another issue with this patch: in Solaris, direct I/O is done by
invoking directio(DIRECTIO_ON); see
<http://docs.sun.com/db/doc/816-0213/6m6ne37so?q=directio&a=view>.
Is Solaris direct I/O a direct analog to Linux direct I/O, or are
there subtle differences in semantics that should be made visible to
the users of GNU "dd"?

  parent reply	other threads:[~2004-04-07 20:47 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-04-06 22:03 Andy Isaacson
2004-04-07  0:33 ` Andrew Morton
2004-04-07 16:21   ` Bruce Allen
2004-04-07 16:42     ` Andrew Morton
2004-04-07 17:31   ` Andy Isaacson
2004-04-07 18:18     ` Andrew Morton
2004-04-07 19:24       ` Andy Isaacson
2004-04-07 19:34         ` Andrew Morton
2004-04-07 19:47           ` Andy Isaacson
2004-04-07 20:03             ` Andrew Morton
2004-04-07 20:43               ` Andy Isaacson
2004-04-07 21:00                 ` Valdis.Kletnieks
2004-04-07 21:35                 ` Bruce Allen
2004-04-08  6:56                   ` Paul Eggert
2004-04-08 11:07                     ` Jim Meyering
2004-04-08 19:32                       ` Paul Eggert
2004-04-08 19:51                         ` Paul Jarc
2004-04-08 21:34                         ` Jim Meyering
2004-04-08 16:23                     ` Philippe Troin
2004-04-08 20:20                       ` dd patch to remove noctty Paul Eggert
2004-04-08 21:40                         ` Jim Meyering
2004-04-09  0:37             ` dd PATCH: add conv=direct Anton Blanchard
2004-04-09  1:42               ` Wim Coekaerts
2004-04-10 21:28                 ` Jim Meyering
2004-04-07 20:46       ` Paul Eggert [this message]
2004-04-07 21:06         ` Andrew Morton
2004-04-07 21:09         ` Andy Isaacson
2004-04-07 19:12     ` Miquel van Smoorenburg
2004-04-07 20:14       ` Andy Isaacson
2004-04-07 22:02 ` Nathan Straz
2004-04-07 22:09   ` Andy Isaacson
2004-04-08 11:44     ` Miquel van Smoorenburg

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87vfkbms7s.fsf@penguin.cs.ucla.edu \
    --to=eggert@cs.ucla.edu \
    --cc=adi@hexapodia.org \
    --cc=akpm@osdl.org \
    --cc=bug-coreutils@gnu.org \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

Powered by JetHome